查询词典 selectivity

In light of this, the paper discusses the influence of accrual of provisions on accounting information from the perspective of selectivity of system.

彻底弄清会计制度的可选择性，对会计信息的影响，对杜绝整个社会会计信息失真问题，是非常必要的。

The effects of various reaction conditions were studied by GC analysis. Reaction time has slight effect on the conversion of acenaphthene. The selectivity of N-phenyl aminoacenaphthene increases with reaction time. Biacenaphthenyls or N-phenyl aminoacenaphthene is in the majority, 77.6% or 90.2% when the molar ratio of AlCl3 to acenaphthene is 1.2 and 2.4 respectively.

GC考察了不同反应条件对苊转化率和产物选择性的影响，时间对苊转化率影响不大，N-苯基氨基苊的选择性随着时间增加而增大；随着AlCl3用量的增加，苊转化率和N-苯基氨基苊的选择性随之增加；AlCl3与苊的摩尔比为1.2和2.4时，产物中联苊和N-苯基氨基苊的选择性分别达到77.6%和90.2%。

Selectivity of acetal was obtained over the Cu/HY-25 catalyst at the temperature of 413K.

通过铜盐与酸功能组分的匹配，以醋酸铜和HY-25分子筛制备的催化剂，在413K生成乙缩醛的选择性大于80％。

A novel Pd／C catalyst with high activity,high selectivity and good stability developed by our group was used for the hydrogenation of N-（3-nitro-4-methoxyphenyl）acetamide into N-（3-amino-4-methoxyphenyl）acetamide in methanol and water,respectively.

笔者开发了一种高效的Pd／C催化剂，分别选用甲醇和水作为反应溶剂，实现了高活性、高选择性和高稳定性地催化加氢制备N-（3-氨基-4-甲氧基苯基）乙酰胺。

Study of the mesh selectivity of diamond and square mesh codend of two-stick swingnet;2. In order to assess the size selectivity for fishes of beam trawl fishing in offshore of the East China Sea,experiments of codends with different mesh configuration,including diamond mesh, square mesh and turned through 90° diamond mesh(T90) in 4 sea trials have been carried out and catch data were collected by comparative fishing method.

选择性分析结果显示，对于短吻舌鳎，横向使用的菱形网目网囊L50(50%选择体长)最大，而SR最小，菱形网目网囊L50最小，而SR最大；对于棘头梅童鱼和小黄鱼，菱形网目网囊的L50最小，SR最大，横向使用的菱形网目网囊L50最大，而方形网目网囊SR最小；除不同结构的网目扩张程度不同以外，鱼体体型结构的特殊性以及网囊结构也可能是导致选择性差异的主要原因。

Many hydrolyses are metalloenzymes, which lead to substrate selectivity, reaction selectivity and stereoselectivity.

酶是一种重要的生命物质，水解酶大多是有基质选择性，反应选择性和立体选择性的金属酶。

The degree of hydrogenation of methyl benzoate might be controled by adding the promoters and changing the nano-size of ZnO. For hydrogenation of methyl benzoate to benzaldehyde, the active-structure of a catalyst should be modified to decrease the absorption of benzaldehyde on the surface of it, because benzaldehyde absorbed is hydrogenated easily. Using 30-40％ZnO/γ-Al〓O〓 or Li-30％ZnO/γ-Al〓O〓, a higher selectivity to benzaldehyde is obtained. Hydrogenolysis of methyl benzoate to toluene or benzene is carried out effectively using a catalyst modified. For instance, 45.3％ selectivity to benzene and 100％ conversion of methyl benzoate at 420℃ was obtained over 10％ZnO/MCM-41 with the nano-size particles of ZnO (2.4nm).

也可以通过助催化剂的添加和活性组分的纳米化，并根据苯甲酸甲酯多步加氢反应的特点实行加氢深度的调控：苯甲酸甲酯选择性加氢制苯甲醛中，由于苯甲醛容易进一步加氢，需要对活性结构进行调变，以减弱苯甲醛的吸附，使用30-40％ZnO/γ-Al〓O〓催化剂或Li调变的Li-30％ZnO/γ-Al〓O〓催化剂，可获得较高的苯甲酸甲酯加氢制苯甲醛的活性；采用同样的方式，苯甲酸甲酯选择性氢解为甲苯或苯也获得了较好的结果，如使用ZnO纳米化的10％ZnO/MCM-41催化剂，在420℃，可获得45.3％的苯选择性，苯甲酸甲酯完全转化。

In this thesis, this system is used for epoxidation of propylene and styrenewith good results. The solvent effect is investigated for epoxidation of styrene. In the mixedsolvent of dimethyl phthalate / TBP or phenyl ether / TBP, the selectivity for styreneoxide is good but the conversion of styrene is low due to the coordination to thecatalyst of the solvent. When part of dimethyl phthalate or phenyl ether is replacedby toluene, the conversion increases and the selectivity keeps constant.

邻苯二甲酸二甲酯或二苯醚等与磷酸三丁酯的混合溶剂中环氧化的选择性较高，但由于溶剂对催化剂的配位作用抑制了催化剂的活性，苯乙烯转化率很低；当部分的邻苯二甲酸二甲酯或二苯醚被甲苯取代后，苯乙烯的转化率提高，生成环氧苯乙烷的选择性不变。

Underoptimal conditions, in toluene / dimethyl phthalate / TBP, after EAHQ was oxidizedwith 〓, then the catalyst and styrene were added, the conversion of styrene basedon EAHQ is 68%, the selectivity for styrene oxide based on styrene is 92% and theTON of the catalyst is 500; in toluene / phenyl ether / TBP, epoxidation of styrenewas performed with 〓 generated in situ, the conversion is 46%, the selectivity is94% and the product can be separated by distillation under reduced pressure.

优化条件下，甲苯／邻苯二甲酸二甲酯／TBP(2／2／1，体积比)中，EAHQ先用〓氧化完全后，再加入催化剂A和苯乙烯进行环氧化反应苯乙烯相对于EAHQ的转化率为68％，生成环氧苯乙烷的选择性为92％，催化剂A的TON达到500；甲苯／二苯醚／TBP(1／3／1，体积比)中，原位生成〓条件下苯乙烯相对于EAHQ的转化率为46％，生成环氧苯乙烷的选择性为94％，产物可通过减压蒸馏分离。

Results All the cumulate mortalities were 100%. The needed time of the test without selectivity under (18±1 )℃ is 8-9 days and under (24±1 )℃ is 2-4 days. The needed time of the test of selectivity under (18±1 )℃ is 9-10 days and under (24±1 )℃ is 3-5 days.

结果 无选择性实验在(18±1)℃条件下耗时8～9d，(24±1)℃条件下耗时2～4d，累积死亡率均达100%；选择性实验(18±1)℃条件下需9～10d，(24±1)℃条件下需3～5d，累积死亡率可达100%。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。